It is common practice to form solid coatings upon electric current transformers to afford structural stability, corrosion resistance, and enhanced aesthetics. Such coatings also help to minimize vibration of the coil stack lamina, and to thereby attenuate the audible hum that applied currents would otherwise tend to produce.
The plates from which transformer stacks are constructed are normally coated with a lubricating oil to aid in assembly; needless to say, therefore, any superimposed coating formulation must be capable of curing in the oil-laden environment. Although compositions known in the art are well-adapted for such applications, it is not believed that there has heretofore been provided a satisfactory method for producing an encapsulating coating upon a transformer coil stack without the undesirable displacement or dissolution of the oil, and while enabling the thorough curing of the coating composition, as is essential to the proper functioning of the transformer.
It is therefore the broad object of the present invention to provide an effective and facile method for the production of a fully cured solid coating upon a laminate article, and in particular upon a transformer coil stack, which coating affords structural strength and stability, enhanced aesthetics, and protection to the part, while also serving to bond the lamina to one another so as to minimize vibration and humming.
A more specific object of the invention is to provide such a method in which the laminated plates are lubricated with oil, and in which the coating composition extends between confronting plates and is effectively and thoroughly cured, to leave virtually no unreacted polymerizable material.
Other objects of the invention are to provide a laminate article consisting of a stack structure on which is formed a solid coating, wherein fully cured fillets of the coating material are disposed between the plates of the structure, and serve to bond the marginal portions to thereby attenuate vibration.